Railway traffic controlling apparatus



May z, 1939. R, AMCANN 2,166,766

l RAILWAY TRAFFIC GONTROLLING APPARATUS Filed March 17, 1958 4 sheets-'sheet 1 l l 5 @89H95 L IZP 1,4m 1K I @f1/VK /Jff /fp am wir ` im I VL* mvENToR Hana/dA. Calm.

HIS ATTOR N EY May2,1939. y R-AMCCANN Y 2,156,766

RAILWAY, TRAFFIC CONTROLLING APPARATUS Filed March 17', 1938 '4 Sheets-Sheet 3 4&1 ,J Vf] y *+19 1T 5T IM *541 r :l 13 I l nl 4LS 7m SES IWS' 3h15' 10.415 6,415 figs im 5111 lNvz-:NroR

Ranald 'Cann. 4

H15 ATToR'NEY May 2, 1939 R. A. MCCANN 2,156,766

RAILWAY TRAFFIC CONTROLLING APPARATUS Fz'g. Il.

HIS ATTORNEY Patented May 2, 1939 RAILWAY TRAFFIC CONTROLLING APPARATUS Ronald A. McCann, Swissvale, Pa., assignor to The VUnion Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania ,Application March 17, 1938, `Serial No. 196,435

27 Claims.

My invention relates to railway traffic controlling apparatus, and more particularly to an interlocking control system for governing the movement of traffic through a track layout comprising 5 a plurality of track sections interconnected by track switches which may be variously arranged to form different traffic routes.

One object kof my invention is the provision of an improved all-relay route interlocking sys- 10 tem for operating the switches and signals for the different traffic routes under the control of inanually .operable levers, push buttons or the like, which are lpreferably mounted on the track diagram in locations corresponding to the ends of 15 the respective routes.

Another object of my invention is the lprovision of improved means whereby one or more of the track switches may be operated as required to establish a route Aby momentarily closing two contacts associated with the `entrance and exit ends, respectively, of the representation of that route on the track diagram. A furtherobject of my invention resides in the provision in a system of this character of means for .locking each gr, switch of a route whensuch route is fully established and for automatically clearing a signal to permit the movement of traine over an established route only when such locking is eiiective. Other objects, purposes and features of my in- .".o Vention will be pointed out as the description proceeds.

My invention is an improvement upon those disclosed inthe copending vapplications for Railway traffic controlling apparatus, Serial No.

3 `118,609,1iled Dec. 31, 1936, by John M. Pelikan; Serial No, 89,602, filed July 8, 1936, by R. A. McCann & S. Young; Serial No. 171,923, led Oct. 30,119.37, by H. S. Young; in the copending applications for Interlocking control apparatus,

`.40 Serial No. 14,868, iiled April 5, 1935, by E. M.

Allen & H. A. Thompson; and Serial No. 726,957,

filed May 22, 1934, by L. Spray; andain the copending applications for Multiple control apparatus, Serial No. 561,422,1'lled Sept. 5, 19.36, by L.

E. Spray; and Serial No. 323,28.6,-ii1ed Dec.1-3, 1928,

by L. E. Spray.

I shall Adescribe one form oi apparatus embodying my invention, and shall lthen point out the novel :features thereof in claims.

Referring to the accompanying drawings, Fig.

l Yillustrates a typical control panel containing the control levers `or buttons `for controlling Athe apparatus .of myinvention `and including Va track diagram which is a miniature :representation of 55 the track `layoutto lbe controlled. Fig. 5 shows,

in the upper portion, a plan of the track layout to which the diagram `of Fig. 1 corresponds, whileFigs. 2 to 11, inclusive, takentogether, illustrate diagrammatically the circuits for a route interlocking system `for controlling the switches 5 and signals of Fig. 5 in accordance with my invention.

Similar reference characters refer to similar parts in each of the several views.

Inorder to simplify the description, I shall first 10 explain the functions of the several parts of my apparatus, and shall then describe its operation under selected conditions in detail.

The track switches shown `in the track plan of Fig. 5 are identified by odd numbers l, 3 and 5, 15 and the wayside signals bythe even numbers 2, 4, 6,8, lll and l2. For the guidance of the control operator, the corresponding numbers are shown on the control panel of Fig. 1 adjacent the switchesof the diagram and the respective con- ,w trol levers. The two switches of a cross-over bear the same :number but are `disti-nguished by the suffixes A and B, respectively, on the track plan, `and similarly, in the case of multiple arm signals 4 and 8, the suiilx A designates the top arm or high .speed signal, and C a slow speed signal. The single arm signals 2, 6, IB and I2 are also slow speed signals. Each slow speed signal also serves as `a call-on signal which may be cleared to admit a train to an occupied .3U block.

In .the circuit plans, each relay or lever is identied `:by a letter or combination of letters prefixed by the designation of 1theswitch, signal, or track section with which it is associated, and, in order te `enable the circuits to be more vreadily understood, they .are .arranged in the written circuit `form with similar circuits grouped together inthe same view. In circuits .of this form, the relay contacts are not necessarily shown 'adjacent the respective relays which operate them, .and a contact is identified not only by a number but more particularly by showing the designation of `the relay which operates it above the contact. Furthermorainstead .of showing the local source of current for energizing the relays, I have shown only the terminals, which `are designated by the reference characters 1B and C, referring to the positive or supply terminal and to the negative or common .return terminal, respectively, `of the o source.

'Each of the control levers of Fig. l bears the reference character? and is of the three-position type, being-operable to the left -or `rightirom the normal position as shown. The even-numbered 55 levers 2P, MIP, etc. are route buttons for controlling the relays shown in Fig. 2, While the oddnumbers levers l, 3 and 5 govern the circuits for the switch control relays WR of Fig. 6 and are for controlling the track switches individually and independently of the route control. Each route button P governing traffic movements from left to right may be turned to the right and each route button governing traiflc movements from right to left may be turned to the left to pick up an entrance stick relay bearing the reference ER with a numerical prefix identifying the associated signal. Each route button may also be turned in the oposite direction to that above mentioned to pick up a corresponding exit stick relay XR. Each button P is therefore the equivalent of a pair of push buttons such as are used, for example, in the system of the McCann & Young application hereinbefore referred to, and it will be readily apparent that push buttons may be used in place of the buttons P in the system disclosed herein, if desired.

Fig. 2 shows the route circuits controlled by the entrance stick relays ER and the exit stick relays XR, these circuits including a separate route circuit for each route, each of which includes the winding of a route relay R and contacts of certain switch locking relays LR and indication relays NWP and RWP as hereinafter described. Each route relay R when energized causes the operation of one or more switch control relays WR by means of the circuits shown in Fig. 6 to thereby effect the operation of the corresponding track switches to normal or reverse as required to establish the route, and, jointly with the entrance stick relay ER. at one end or the other, controls a corresponding signal control relayHR in a route network of interconnected circuits shown in Fig. 3. The signal control relay HR corresponding to the energized relays ER and R becomes energized when the route is fully established, and controls the corresponding signal.

The callon signals 4C and 8C are each controlled by a key or push-button CB shown below the corresponding route lever in Fig. 1 by means of a call-on stick relay CO having circuits arranged as shown in Fig. '7.

One feature of my invention relates to the control of the route circuits of Fig. 2 by the operation of the buttons P for the two ends of a route. Considering the route which extends from signal t to signal lil and having the route relay 5-iQR, for example, when lever EEP is moved mo-l mentarily to the right, relay SER picks up over a circuit hereinafter traced in detail. Relay EER is held energized over its stick circuit after lever 6P is restored to normal, and connects terminal B of the source of current to the route circuit including relay G-IQR. When button HBP is moved momentarily to the right, relay IXR picks up, and then upon the restoration of button HJP to normal, relay -IEBR picks up in series with relay iXR, both of these relays being held energized as long as relay SER is energized. The corresponding entrance relay MER for the opposite direction is now rendered inoperative because its circuit includes a back contact of relay MXR.

As hereinafter explained in detail, switches 3 and 5 are operated by relay S-IR to establish route 6-ll, then signal i5 will clear automatically when route S-l is fully established and locked in response to a movement of levers GP and IGP to the right. Signal 6 may be put to stop manually and the route cancelled by mov'- ing lever GP momentarily to the left to operate relay 5KB which has a back contact in the stick circuit for relay EER. Relay S-IR may also be energized by moving levers 6P and HlP momentarily to the left, in which case relay IUER will become energized and relays @XR and 6 -l 0R will be energized in series and the opposing sig nal if) will be cleared. Similarly, signal 4 or hi may be cleared by moving levers dP and IOP to the right or left, respectively, to energize relay d-il The route circuits for the upper track are somewhat differently arranged for two reasons, first, because of the presence of the intermediate signal i2, and, second, because in addition to the normal route 6 8 over switches l reversed and 5A normal there is an alternative route iii-3A over switches iB and 3 normal and 5 reversed. The latter route becomes available automatically when switches i are locked normal due to the presence of a train in that portion of the upper track which is to the left of signal it, and switches 5 are not locked. Route 4-8A is also selected automatically instead of route 5 3 if the individual switch lever 5P is placed in the reverse position. Route 4-8A, and also routes -t-i and 2-8 for train movements from right to left only, may be established by operating the levers at the ends of the diagram as in the case of route G-Hi, but to clear signal 2 or l for a movement from left to right past signal i2 two successive movements of lever l2 to the right are required. The first operation of lever` l2 to the right energizes the exit stick relay HZXR for routes 2-i 2 and f|2. When one of these routes is set up for a movement up to signal i2, a selecting relay IES becomes energized. When this relay is energized, a movement of lever i2 to the right energizes the entrance stick relay lER for the route l2-8. These special features of the appartus are described in more detail hereinafter, but it is believed that it will be clear from the foregoing outline of the operation of the circuits of Fig. 2 that, in each case, the route circuit is established by the momentary operation of the route levers for the two ends of the route, and that the traffic direction is determined in accordance with the relative direction in which the two levers are operated.

In addition to the manual means for cancelling a route, means are provided, as in the Pelikan application hereinbefore referred to, for deenergizing each route circuit automatically as soon as the route is entered by a train by opening the stick circuit for the entrance stick relay. This is accomplished in such a manner that the stick circuit again becomes available after a time sufiicient to insure the release of the route relays, so that an occupied route may be re-established and a slow speed signal cleared by a second operation of the same levers. This arrangement permits a train to enter, at slow speed, a route already occupied by a preceding train, as is often desirable in practice.

Arrangements are also provided such that the high speed signals 4A and 8A may be caused to clear automatically after a through main line train has passed beyond the control limits of the signal. When route lil- 8 or 8-2 is set up, it may be retained to permit the movement of a series of trains by allowing the entrance lever 4P or 8P to remain in its reverse position instead of returning it to normal.

Fig. 4 shows the circuits controlled by the sighal control relays HR of Fig. 3, comprising a signal network of interconnected circuits for controlling the signals of Fig. 5. Each signal has an operating mechanism, designated by the reference character G with identifying prex in Fig. 4, and controlled over a signal circuit which corresponds to the route which such signal governs and which includes various contacts of switch locking and indication relays. vThe signals may be of any desired type, but, as herein illustrated, it is to be understood that they are of the well-known searchlight vtype having mechanism G -of the form disclosed in the E. J. Blake Reissue Patent No. 14,940 of August 31, 1920.

`The high speed signal mechanisms iAG and SAG are each provided with the usual back lock or signal indication relay AGP, as shown in Fig. 4, which is energized only when the corresponding signal indicates stop.

For simplicity, each signal as illustrated is arranged to indicate either clear or sto-p, and the usual circuits for controlling each signal by the next signal in. advance to provide a third indication have been omitted from the drawings since these are not essential to an understanding of the present invention.

Each signal mechanism or group of mechanisms G is provided with the usual approach locking stick relay which is identified by the reference character ALS in Fig. 4. VTo simplify the drawings the circuits: for the locking relaysALS are not shown in detail further than to indicate by dotted line connections that each relay ALS is energized only when both the signal control relay HR and the mechanism G for the corresponding signal are deenergized. The circuits for the approach locking relays are preferably arranged as disclosed in a copending application for Interlocking controlling apparatus, Serial No.

695294, filed Oct. 26, 1933, by Allen & Thompson, but, for an understanding of the vpresent invention, it i-s believed that it will suflice merely to point out that these relays provide the usual time and approach locking of the switches and of opposing signals; thus when a signal assumes the stop position the energization of the associated relay ALS is delayed fora predetermined time interval provided the signal is put to stop manually, this delay being nullied by the release of the corresponding track relay when the signal is `automatically put to stop by a passing train. The approach locking relays ALS control certain section locking relays iES and WS by means oi the circuits of Fig. 8, which relays provide the .usual directional control of the switch locking and function so that when a train enters a route the locking of each switch ahead of the train will be maintained while the locking of each switch in the rear of the train will be released as soon as the corresponding track section is vacated. 1

Referring now to Fig. 45, the track plan shown therein represents the track rails: la and lb vof each .of two main tracks connected by the crossovers I and 5, the lower track being also connected to a siding by a single switch 3. While a specific track layout is disclosed, it is to be understood that the apparatus of my invention is adapted to Vcontrol other track layouts that may involve entirely different combinations of switches and.' signals, the present layout having been chosen to illustrate the principles of my invention in a simple manner. As indicated in the drawings, the tracks are divided into sections by insulated joints y', the detector sections of the upper track which include the track switches bearing the references IT and 5T, while those for the lower track bear the references 3T and 1T. The adjacent approach sections of the two main tracks are designated 8T and 4T, respectively. Each track section is provided with the usual closed track circuit including a track battery 9 and a normally energized track relay in accordance with standard practice, each track relay being identified by the reference character TR with a numerical prex identifying the track section to which it corresponds. Each detector section track relay controls a slow release repeating re lay TZ.

Relays TR and TZ jointly control the above mentioned circuits of Fig. 2 for effecting the automatic cancellation of the routes.

Each track switch o Fig. 5 is actuated by a power-operated switch machine SM, which as herein disclosed may be assumed to be of the type shown in the Zabel Patent Nos. 1,293,290 and 1,413,820. Each switch machine is provided with the usual motor having its operating circuits controlled by the contacts of a polarized switch control relay WR in the manner illustrated in the Willard Patent No. 1,380,452, as indicated da grammatically by dotted line connections in the drawings, and it is to be understood that each switch or switches will be operated to normal, as shown, or to reverse, when the control relay WR is energized and its polar contacts are closed to the left or right, respectively. Each relay WR is controlled by a polar stick relay W, shown in Fig. 6, and each relay W is controlled by the route relays R of Fig. 2, when route control is used, or by the corresponding switch lever P when individual switch control is used. Each relay WR is also controlled by a switch locking relay LR. The locking relays LR are controlled over the circuits of Fig. 9 by the detector track relays TR, of Fig. 5, the approach locking relays ALS of Fig. 4, and the section locking relays ES and WS of Fig. 8.

Each switch machine is provided with the usual switch circuit controller, as disclosed in the Zabel patents hereinbefore referred to, for controlling a polarized switch indication relay WP, as indicated diagrammatically by dotted line connections in Fig. 5. For an understanding of the present invention, it will suice to point out that when both switch machines SM of the cross-over l or 5 are locked normal or reverse, the corresponding relay IWP or SWP will be energized and its polar contacts closed to the left or right, respectively, and that relay SWP is similarly controlled by switch machine 'JSM for the single switch 3.

Each switch indication relay WP is provided with a pair of repeating relays NWP and RWP each of which is energized only when the polarized relay WP is energized in a position corresponding to that of the associated switch control relay WR.

As will be hereinafter pointed out in detail, the locking relays LR together with the switch CII indication relays NWP and RWP control the route circuits of Fig. 2 in such a manner that a route circuit for a relay R can not be completed unless each switch of the route is either unlocked or already occupies a position in accordance with the route. The indication relays NWP and RWP also control the route network circuits of Fig. 3. It follows that when any route circuit of Fig. 2 is closed by the operator, the corresponding signal control relay HR of Fig. 3 will become energized d (If in response to the' operation of the switch indication relays NWP or RWP as soon as the corresponding route is established through the track layout. Each relay HR, upon becoming energized, will release the corresponding approach locking relay ALS, which in turn releases one or more section locking relays ES and WS and switch locking relays LR. The latter relays will then open the route circuits of Fig. 2 for all routes which conflict with the established route, the control levers P for all such routes being thereby rendered inactive.

The locking relays ALS and LR and the indication relays NWP and RWP also control the signal network circuits of Fig. 4. The circuit for each signal mechanism G includes a back contact of the locking relay LR for each switch of the route which such signal governs, as in the Young application hereinbefore referred to, so that the signal can not be cleared unless all of the locking relays for the switches of the route assume their deenergized positions. Time locking of opposing signals is provided in Fig. 4 by including in the circuit for each mechanism G a front contact of the approach locking relay ALS controlled by the opposing signal for the same route.

Fig. l shows the circuits for a group of directionally controlled stick indication relays ESK and WSK which control lamps. for illuminating the tracks of the track diagram of Fig. 1. The relays ESK and WSK are controlled by the signal control relays I-IR and function in such a manner that when one of the relays HR of Fig. 3 is energized, a series of indication relays for the corresponding direction, east or west, become energized successively in tandem, including one relay for each track section of the corresponding route. Each indication relay has a stick circuit controlled by a back contact of the track relay TR for the corresponding track section, so that it will remain energized after a train has entered the route and until that section is vacated.

It is to be understood that the track diagram of Fig. l is made up of a plurality of substantially linear portions or indicators K of translucent material, as shown in the Pelikan application hereinbeiore referred to, which portions K are illuminated by lamps bearing similar designations and shown in Fig. 1l. The indicators AK for the approach sections are illuminated by red lamps r when the sections are occupied, while the indicators for the route portions, which are normally dark, are arranged to be illuminated when a route is set up either by a white lamp w or a red lamp r.

Fig. 1l shows, in the upper part, the circuits for the lamps of the track diagram, and it will be seen that the white lamps w are controlled by one or more of the indication relays ESK and WSK over front contacts of the track relays TR, while the red lamps 1' are similarly controlled over back contacts of relays TR. Furthermore, those portions NK and RK which represent the branch tracks extending in the trailing direction from a track switch are selectively controlled over front contacts of the switch indication relays NWP and RWP. The lamps for the sections RK are also controlled by an interrupter relay CT over back contacts of the switch indication relays to provide a hashing indication when a switch is in transit from one of its operated positions to the other.

The track diagram is normally dark, but, when the operator operates a pair of levers P to set up a route, the corresponding route relay R will become energized and actuate the switch controll relay WR for each switch of which the position is diierent from that required for the route, thereby deenergizing the relays NWP and RWP for that switch and causing the lamp w for the corresponding section RK of the track diagram to display a ashing indication until the switch completes its operation in accordance with the route. When all the switches of the route are in the proper positions, a signal control relay HR becomes energized and causes the energization in tandem of a series of relays ESK or WSK, thereby lighting the white lamps for the corresponding portions of the track diagram so that a substantially continuous illuminated white line corresponding to the established route is displayed. When a train enters the approach section, the red lamp for that section is lighted, and as the train enters each detector section of the route, the illumination of the corresponding portions of the diagram changes from white to red, and, as each section is vacated, the corresponding portions become dark.

The track diagram also includes an indicator K for each signal, each comprising a green lamp g and a red lamp r, which in the form illustrated are located adjacent the lever for the entering end o1" the route which the signal governs, the circuits for these lamps being shown in the lower part of Fig. 11. When any entrance stick relay ER becomes energized, the adjacent red lamp is lighted. This lamp remains lighted if the route is not available. When the route becomes established and the corresponding signal has been cleared, the red lamp is extinguished and the corresponding green lamp is lighted.

The signal indication lamps are arranged to be controlled also by an interrupter relay CT, so as to provide additional information by the display of flashing indications. Thus each slow speed signal when clear causes the display of a ashing green light, while each high speed signal 4A or 8A when clear causes the display of a steady green light. When a signal is put to stop manually, the switch locking will in some cases remain effective for a predetermined time interval as already explained, and during this interval the operator will be unable to establish a conflicting route. In order to aid the operator in setting up the new route as soon as it becomes available, the circuits are so arranged that the red signal indicating lamp will flash from the time when a route is manually cancelled until the locking is released, and will then become dark.

I shall now describe the operation of my apparatus under different assumed conditions. I shall rst assume that the apparatus is in the condition shown in the drawings, and that the operator desires to pass a train from section 4T, Fig. 5, over route 4 8, past signal I2 to section 8T. When the train enters section 4T, the release of track relay 4TH, closes back contact I3, Fig. l1, to close a circuit for the red lamp r of the approach indicator 4AK, this portion of the track diagram being thereby illuminated to inform the operator of the approach of the train.

To set up route 4 8 for a movement from left to right, the operator will rst set up route 4-I2 and then set up route I28, as already explained, that is, he will rst operate levers 4P and IZP to the right successively in that order. The momentary operation of lever 4P completes a circuit for relay 4ER which may be traced in Fig. 2 from terminal B, normal contact II of lever 2P, right-hand contact I4 of lever 4P, relay 4ER,

back contact I of relay 4XR, and front contact I6 of track relay 'II'R to terminal C. Relay AER picks up and closes a stick circuit from terminal B, over the iront contact I'I and winding of relay 4BR, and contacts I5 and I6 to terminal C. i This stick circuit serves to hold relay 4BR energized until the train enters the route and contact I6 opens or the route is cancelled manually by energizing relay 4XR to open contact I5. `Relay AER, upon becoming energized, closes` a circuit for indicator 4K, Fig. 11, to thereby display a red light at the entrance to route ii-I2 on the track diagram. This circuit may be traced from terminal B, back contacts I8 and I9 of signal ,mechanisms 40G and 4AG, front contact 2U of relay IIER, and red lamp r of indicator 4K to terminal C.

Relay 4ER also closes contacts 2l, 22 and 23, Fig. 2, to connect terminal B to the left-hand end of the three route circuits for route AII-I2, route 4-8A (over 5 reversed), and route 4-I0, respectively. Without tracing these circuits in detail, it will be apparent from the drawings that the first includes relay 4-I2R and is open at front contact 24 of relay IZXR, that the second includes relay d-SAR and is open at back contact 25 of relay ILR and at iront contact 26 of relay BXR, while the third includes relay 4-IOR and is open at front contact 21 of relay IUXR.

When lever I2P is operated toI the right, a circuit is closed from terminal B, right-hand contact 28 of lever IZP, back contacts 29 and 3l) of relays `I2-8R and I2S, and relay I2XR to terminal C. Relay IZXR picks up, but relay A-IZR does not pick up at this time because, although terminal B is connected to the left-hand terminal of its winding over front contact 2l, terminal B is also connected to the right-hand terminal of its Winding over co-ntacts 28, 29, 3U, 24 and 32, so that relay 4-I2R is short-circuited, and the full battery voltage is impressed upon relay IZXR.

When lever I2P is restored to normal to open contact 2B., the short-circuiting connection is removed, permitting current to flow iro-m terminal B through relays 4-I2R and I2XR in series to terminal C. Therefore when contact 2t opens, relay 4-I2R picks up over the circuit from terminal B, front contact 2! of relay 4ER, front contact 3l of relay ILR, relay 4I2R, front contact 32 oi relay 4ER, front contact 24 and windwill thus become energized over a stick circuit including its own Winding and the winding and front contact 24 of relay IZXR, in series, and Will close a circuit from terminal B, front con.- tact 33 of relay 4-I2R, and relay I2S to terminal C. Relay IS will therefore pick up and open back contact 3D in the pick-up circuit for relay IZXR and prepare the pick-up circuit for relay -I 2ER by closing iront contact 3Q. When relay 4-I2R becomes energized, it closes its front contact 34, Fig. 6, completing the reverse energizing circuit for relay IW which includes the lower winding of that relay. Relay IW is a two-position relay arranged to remain in its last-operated position when deenergized, and it now reverses and completes the reverse operating circuit for the polarized switch control relay IWR from terminal B, reverse contact 35, front contact 36 of relay ILR, relay IWR, front Contact 31 of relay ILR, and reverse contact 38 of relay IW to terminal C.

Relay IWR therefore reverses and operates the switch machines IASM and IBSM to reverse switches I, and alsoopens its left-hand polar contact 39, Fig, 5, to release relay INWP.

Relay INWP, upon releasing, opens various front contacts in the circuits of Figs, 2, 3, 4, and 1l., and by closing back contact 4I, Fig. 11, completes a circuit from terminal B, back contacts 40, 4I and 42 of relays CT, INWP and IRWP, front contacts 43 and 44 of relays 'ITR and ITR, and lamp w of indicator IRK to terminal C. Relay CT is energized over its own back contact liti and so operates repeatedly to open and close the lamp circuit. Lamp w of the portion IRK of the track diagram will therefore display a nashing indication as long as the switches I are in transit. As already pointed out, lamp T of the signal indicator iK is also lighted at this time.

When the switches I lcomplete their movement and become locked reverse, the polarized switch indication relay IWP, Fig. 5, becomes energized in the reverse direction, completing a circuit from terminal B over its neutral contact 46 and reverse polar contact 41, relay IRWP, and reverse contact 39 of relay IWR to terminal C.

Relay IRWP therefore picks up and closes contacts in the circuits of Figs 2, 3, 4, 8, 1.0 and l1, In Fig. 3, a circuit is completed from terminal B, over front contacts 48, 49, 5U and Eil of relays IZXR, Ii-JIZR, IRWP and AER, and relay 4BR to terminal C. Relay IHR therefore picks up, closing contact 52, Fig. 10, to complete a pick-up circuit for the indication relay 'IESK- Relay TESI/, upon becoming energized, closes contact 53 to complete a pick-up circuit over front contact 54 of relay IRWP for rela-y IESK, which also becomes energized. Relay 'IESK, upon becoming energized, closes contact 55, Fig. 11, to complete a circuit over front contact 56 of relay ITR to light the white lamp w for portion 'IK of the track diagram. A similar circuit is closed over contacts 51 and 53 of relays GESK and iTR to light the lamp w for portion IK, and the nashing lamp w of the portion IRK now becomes steadily lighted over the circuit including front contacts 59, d2, 43 and 44 of relays IESK, IRWP, 'ITR and ITR. A representation of the established route 4-I2 is now displayed on the track diagram of Fig, l as a substantially continuous white line comprising the illuminated portions 1K, IRK and IK.

The energization of relay 4I-IR also opened back contact Ell, Fig. 4, releasing the approach locking stick relay 4ALS, thereby opening contact 6I, Fig. 9, to release the locking relay ILR. Upon releasing, relay ILR opens contacts in Fig. 2 bridging the open contacts of relay INWP in the circuits for the conflicting route relays 2-I2R, 4-8AR and 4--IllR. Relay I LR also opens contact 3! in the circuit for the energized route relay 4-I2R, but this is without effect because that contact is now bridged by the closed contact 62 of relay IRWP. It will be clear that the route circuits for all routes which conflict with route 4-I2, that is, for all routes except 6-8 and 6--I Il are now locked open.

Relay ILR, upon releasing, also opens front contacts: 36 and 31 in the reverse operating circuit for relay IWR, Fig. 6, and at its back contacts closes the reverse holding circuit for that relay, locking the switches IA and IB reversed. At the same time, relay ILR closes back contact 65, Fig. 4, to complete the circuit for the signal mechanism 40G. This circuit may be traced from terminal B, front contacts 63 and 54 of relays ALS and IZXR, back contact 55 of relay ILR, iront contacts 66, 61, G8 and 69 of relays IRWP, 4HR, IRWP and IIAGP, mechanism 40T, and front contact 60 of relay 4I-IR to terminal C. Mechanism 4CG therefore becomes energized to cause signal 4C to indicate proceed at slow speed.

Mechanism 40G, upon becoming energized, opens an additional contact 10 in the circuit for relay 4ALS, and also opens contact I8, Fig. 1l, to extinguish the red lamp for the signal indicator 4K, but a circuit is closed from terminal B, back contact 48 of the interrupter relay CT, front contact "II of mechanism llCG, and lamp y of indicator 4K to terminal C, thereby displaying a ashing green light to indicate that the slow speed signal 4 has been cleared.

I shall now assume that the operator moves 1evers I 2P and 8P momentarily to the right to clear signal I2. Since relay I2S is now energized, the operation of lever I2P completes a circuit over right-hand contact 28, back contact 29, front contact 30, relay IZER, resistor 12, and front contact 13 of relay 5TR to terminal C. Relay 2ER picks up and closes a stick circuit from .terminal B over the front contact 'M and winding of relay I2ER, resistor '|2, and contact 'I3 to terminal C. This stick circuit serves to hold relay I2ER energized until the train enters the route and contact '|3 opens or until the route is manually cancelled. Relay IZER, upon becoming energized, closes a circuit for lamp r of indicator I2K which may be traced in Fig. 11 from terminal B, back contact 15 of mechanism |2G, front contact 16 of relay IZER, and lamp r to terminal C, so that a red light is displayed on the track diagram as soon as lever I2P is operated. When lever 8P' is operated to the right, a circuit is closed from terminal B, normal contact of lever IUP, righthand contact 18 of lever 8P, and relay 8XR to terminal C. Relay 8XR picks up to close its front contacts, and, when lever 8P is restored to normal, current will flow through relays I2-8R and 8XR in series over a circuit similar to the one for relays 4-I2R and I2XR hereinbefore described. This circuit may be traced from terminal B, front contact 19 of relay I2ER, relay I 2-8R, front contact 80 of relay 5LR, normal contact 8| of switch lever 5P, back contact 82 of relay SER, front contact 83 and winding of relay 8XR to terminal C. Relay I2-8R will 4therefore pick up in series with relay 8XR and complete a circuit in Fig. 3 from terminal B, back contact 84 of relay BER, front contacts 85, 86 and 81 of relays SNW'P, I2-8R and |2ER, and relay I2HR to terminal C. Relay I2-8R closes contact 88, Fig. 6, to complete the normal circuit for relay 5W controlling the switch control relay SWR, Fig. 6, so that relays 5W and SWR are held normal.

Relay |2HR, upon becoming energized, closes contact 89, Fig. 10, to complete the pick-up circuit for relay 5ESK, and the latter relay closes contact 90, Fig. 11, to complete the circuits for the lamps w of the portions BANK and 5K of the track diagram to complete the route indication. Relay IZHR also opens` back contact 9|, Fig. 4, releasing relay I ZALS, which relay by opening contact 92, Fig, 9, releases relay 5LR. In Fig. 2, relay 5LR opens contacts in the circuits for each of the route relays I2-8R, 4--8AR, 4-I 0R, G-BR and 6--IOR. The energized route relay I2-8R, however, is not interfered with because front contact 80 of relay 5LR in the circuit for that relay is bridged by contact 93 of relay SNWP. The circuit for route |2-8 cannot now be interfered with by a movement of the switch lever 5P because the lever contact 8| is shunted by back contact 80 of relay 5LR. The circuits for the conflicting route relays ll-8AR and 4--I9R were opened when route 4-I 2 was set up, as already described, but route 6 8 is now also a conflicting route and its route circuit is opened at contact 94 of relay 5LR. The route circuit for route E-ID remains available because contact 95 of relay 5NWP is closed.

Relay 5LR, upon releasing, also opens front contacts 96 and 91 in the circuit for relay SWR, Fig. 6, and at its back contacts closes the normal holding circuit for that relay, locking the switches 5 normal, and at the same time closes back contact IDI, Fig. 4, to complete a circuit for signal mechanism I2G. This circuit may be traced from terminal B, front contact 98 of relay SALS, back contact 99 of relay BHR, front contact |00 of relay ENWP, back contact ISI of relay 5LR, front contact |02 of relay I2HR, mechanism IZG, and front contact 9| of relay IZHR to terminal C. Mechanism IZG therefore becomes energized to clear the slow speed signal I2.

Mechanism |2G, uporr becoming energized, opens an additional contact |03 in the circuit for relay |2ALS, and also opens contact 15, Fig. 1l, to extinguish lamp r and closes contact |84 to cause lamp g of indicator I2K to liash to indicate that signal I2 has been cleared.

I shall now assume that the approaching train passes signal lC at clear and enters track section 1T. Track relay ITR releases, deenergizing relay '|TZ, Fig. 5, and opening contact I6 in the circuit for relay 4ER. Relay 4ER releases, opening contact 2| to cause relays 4-I2R and |2XR to release, and opening contact 5I to cause relay llHR to release. Relay EHR opens front contacts 6U and @'I, Fig. 4, deenergizing mechanism 4CG to restore signal 4C to stop to permit relay SALS to be reenergized. Relay LR is now held released by the open contact |95 of relay TTR, Fig. 9, and, when the train enters section IT, by contact |06 of relay ITR so that switches IA and IB remain locked until the train vacates sections TT and IT.

When the train enters section 5T, relay GTR releases, opening contact 13 to release relay IZER, and then relays |2-8R, 8XR, IZHR and mechanism IZG become deenergized, restoring signal I2 to stop, and permitting relay IZALS to be reenergized. Relay 5LR is now held released by relay ETR, so that switches 5A and 5B remain locked until the train vacates section 5T.

When the train occupies section iT or IT, relay I 2S, Fig. 2, is held energized over back contacts I l or |08 of these relays. The original energizing circuit for relay I ZXR is therefore open at back contact 30 of relay I2S, but, nevertheless, the operator may clear signal 4C to permit a second train to enter the occupied section IT by reoperating levers 4P and I2P. It will be apparent from an inspection of Fig. 2 that a pickup circuit for relay @ER is now available over back contact |09 of relay |TZ, or over front contact I of relay TTR if section 'IT has been vacated, and that a pick-up circuit for relay IZXR is available over back contact IIO of relay ITZ. Signal I2 may be cleared to permit the second train to enter the occupied section 5T because a, pick-up circuit for relay IZER is available over front contact 30 of relay I2S and back contact III of relay 5TZ. Signal I2 may also be cleared under the following condition; assume that a train moves from right to left past signal 8 at clear into section IT. Signal 8, when cleared,

.released relay 8ALS, which by opening contact H2, Fig. 8, released the section locking relay `I WS. A back contact H3 of relay IWS provides a pick-up circuit for relay I'2S, so that relay IES will become energized to provide a pick-up circuit for the entrance relay IZER, as in the case previously described.

. Considering now the operation of the indication apparatus in response to the train movement over route 4--8, it will be noted that the signal indicator 4K becomes dark when the train enters section 1T.. This `is because when the signal mechanism 40G releases, itt opens contact lfl, Fig. 1l, to deenergize lamp g of portion 4K, and relay 4ER releases to open front contact 2li in one circuit for lamp r of portion AK, while back contact II4 in the other circuit oi that lamp is opened when relay 4A'LS picks up. The approach indicator IAK becomes dark when the train `vacates secticn 4T and relay 4TR picks up, as is obvious. `The release of relay i1-IR opens the pick-up circuit for relay 'IESK, but relay 'lESK is now held energized over a stick circuit including its own v.iront contact I I5.and back contact II'B of relay ITR. The release of `relay ETR also opens front contacts 56 and 43, Fig. 11, and closes back contacts II'I .and 4.3 to cause the indication of the track portions TIK and IRK to change from white to red, while the white lamps for the portions IK, SANK and K which indicate the sections ahead oi the train remain lighted.

When the train enters section IT, relay ITR releases to complete a stick circuit for relay IESK over its front contact IIB and a back contact IIS of relay ITR, and relay ITR opens front contact 58 and close-s back contact |20 to change the indication of the track portion IK from White to red. When the train vacates section IT, relay 'ITR picks up and opens contact III, causing lamp r for portion IK to become dark, .and releases relay lESK, which opens contact 55 to cause lamp `tu of portion 'IK to remain dark, but a new circuit is established for lamp 1'` of portion IRK over frontl contact 43 of relay 'ITR andback contact 44 of relay ITR so that red lamp r for portion .IRK remains lighted. When the train enters section 5T, relay ETR releases to complete a stick circuit for relay `SESK over its front contact I2! and a back contact I22 of relay 5TR, and relay ETR opens the circuits for lamps w and closes those `for lamps r oi portions `BANK and 5K. At `the same time, the release of mechanism IZG and relay IZER, and the energization of relay IZALS causes the signal indicator I2K to become dark. It will be app-arent that when the train vacates section IT portions IRK and IK of the diagram will become dark, and when it vacates section 5T, portions 5ANK and 5K will become dark.

It will be noted that at least one red lamp for each track section, such for example as the one controlled over back contact II'I of relay 1TB., becomes lighted when the corresponding track section is occupied even though no route has been set up. These lamps, therefore, in addition to indicating the movement of a train over an established route also indicate the release of a track relay and the consequent locking of the switches under other conditions, such for example as would occur if a car .should drift into a detector track section past a stop signal.

It is believed that, in view of the foregoing detailed description of the operation of the appa- .ratus under one set of conditions, its operation under other `corresponding conditions will `be readily apparent without tracingthe circuits in detail. It is `.to be noted, however, that the route circuits for Vcontrolling train movements from right to left are somewhat different from those described because there is no intermediate signal for that direction. A movement of levers 8P and 4P to the left will cause the energization oi relays SER, IZ-BR and IIXR in a manner similar to that already described in connection with the relays flor route 4-12. The series circuit for relays I2`8R .and liXR may be traced from terminal B, front contact 82 of relay 3ER, contacts BI, 80, relay I2-8R, back contact l5), contacts `|123 and I`24 .of relays ILR and AER, front contact |25 and winding oi relay AKR to terminal C. Relays SER, IZ--SR and 4XR control relay i-I 2R over a local circuit which may be traced from terminal B, front contacts I26 and 52'@ of relays SER and I.2--8R, back contact 32 of relay AER, relay 4-Ii2R, front contact 3| of relay ILR, back contact 2| of relay 4ER, resistor IZB, and front contact. #29 of relay IXR to terminal C. Circuits similar to those for route 8-4 just de'scribed are also provided for controlling train movements from right to left over route 8 2.

It may happen that the operator is unable to complete a route by operation of the route levers, due to failure of one or more of the track switches to fully operate, as would be the case, for example, if there were an obstruction in the switch. In such case the operator would employ the individual lever to operate the switch back and forth to remove the obstruction or to restore the switch to its original position.

To do this, it is `necessary to irst release the energized route relays by making a reverse movement of the lever for the entrance end of the route, that is, by moving the lever momentarily to the left in the case oi lever 4P. This will cause relay IIXR. to pick up, opening Contact I5 to release relay 4ER, and relay 4ER by opening its front contacts will release relays fI-I2R and I'ZXR. The intermediate lever IEP is somewhat diiTerentl-y arranged, but a reverse movement of that lever has the same result. A movement of lever I2P to the left connects terminal B over contact 28 to the right-hand terminal of relay I'lER to shunt the relay to cause it to release.

It will be clear from Fig. 6 that each polar 1 stick relay W may be operated individually to the right or left, as required, by momentarily operating the corresponding switch lever to the right or left, provided the switch locking relay LR for the switch is energized and the route relays R are not energized, and each relay W when so operated will control the associated track switch to a cor-responding position as already explained. The portion RK of the track diagram will display the usual flashing indication when the switch is in transit, and will become dark when the switch completes its movement to a position in agreement with relays W and WR. The operator may set up any route by the operation of the .switches individually in this manner, and may then clear the `signal for that route by operating the proper entrance and exit route levers.

I shall now assume that the operator wishes to set up the alternative route {L -8A over crossover 5 reversed, as would be the case, ior example, if he were unable to complete the route set-up for route 4-I2 or 8-4 over switches I reversed but succeeded in restoring these switches to normal. In this case, he would operate the individual switch lever 5P to reverse the switches 5 to set up the alternative route, allowing lever 5P to remain in its reversed position, thereby opening the route circuit for routes 8-4 and |2-8 at contact Si. The route circuit for route -A will then be completed over the reverse contact |36 of the switch lever 5P when the route levers 4P and 8P are operated. When route 4-8A is established, relays ILR, SLR, and ELR will release, and lever 5P may then be restored to normal without interfering with the energized route circuit because contact |30 will be bridged by back contact 25 of relay ILR, and the route circuit over the normal contact 8| of lever 5P will be open at Contact S3 of relay 5NWP.

The alternative route 4-8Aover cross-over 5 reversed may also be selected automatically under certain conditions, as for example, when section |T is occupied so that switches I are locked normal. In that case, relabs ILR and IRWP are both deenergized and consequently the route circuits for routes 4-|2 and 8 4 are not available. If levers 4P and 8P are now operated, the route circuit for route 4-8A will be completed, if that route is available, from terminal B, front contact 22 of relay 4ER, front contact |3I of relay INWP, relay 4-8AR, contacts |32 and |33 of relays SLR and ELR, back contacts 25 and |36 of relays ILR and 8ER, and front contact 26 and winding of relay XR to terminal C.

I shall next assume that levers 4P and IOP have been operated to clear signal 4A, that a train has passed the signal and is occupying route 4-|0, and that the operator wishes to reestablish the route so as to permit a following train to move over it as soon as it is vacated by the rst train.

As in the lcase of route 4-|2, if lever 4P has been operated momentarily to set up the route so that it occupies its normal position when the rst train enters section 1T, the route relays will be released before relay TTZ closes its back contact |09. When this contact closes, it bridges contact i6 of relay I'IR, and levers 4P and IUP may be reoperated to again energize relays 4ER, 4-|DR and IGXR. Relay IHR will be reenergized, but the circuit for mechanism 4AG, Fig. 4, is open at contact |35 of relay 'ITR or contact |36 of relay 3TR, Therefore signal 4A remains at stop, and lamp 1' of indicator 4K becomes lighted and then remains lighted until the rst train vacates the controlling track circuits and then signal 4A will clear automatically. In practice, signal 4A would be a three-position signal controlled by additional track circuits to the right of section 3T, and signal 8A would be similarly controlled, but this has no bearing on the present invention, and the circuits for effecting such control have been omitted.

In case of a series of through train movements to be made, signal 4A or 8A may be caused to clear automatically when each train passes out of the controlling track sections. This is accomplished merely by leaving lever 4P or 8P in its reversed position after picking up the entrance stick relay. Contact I6 of relay ITR in the circuit for relay 4ER will then be bridged by contact |31 of lever 4P so that relay 4BR will remain energized as long as lever 4P remains reversed. Relay BER is similarly controlled, as is apparent from the drawing.

The operator may also permit a second train to enter route 4|0 when occupied by employing the slow speed signal 4C as a call-on signal. In this case, the operator will cause the route relays to remain energized, or will reenergize them, as already described, after the first train has passed signal 4A, and will then operate the call-on key or push button 4GB, Fig. l, completing a circuit, Fig. 7, from terminal B, contact |38 of relay 4HR, contact |39 of relay 4AGP, contact |40 of key 4GB, and relay GCO to terminal C. Relay GCO picks up to complete a stick circuit over contacts |38, |39 and its own front contact MI. Relay ACO also completes a circuit for mechanism 40G, Fig. 4, from terminal B, front contact |42 of relay IUALS, contacts |43 to |49, inclusive, front contact 6l of relay 4HR, contact |50 of relay 4CO, contact 69 of relay AGP, mechanism 4CG, and contact 6D of relay HR to terminal C, thereby clearing signal 4C.

After the second train has passed signal 4C, the operator may cancel the route and restore the signal to stop by moving lever 4P momentarily to the left, as already explained. The slow speed signal 8C is similarly controlled by the call-on push button B, as will be apparent from the drawings.

It has already been pointed out that time locking may be employed in connection with the approach locking stick relays, that is, the energization of relay 4ALS, for example, may be delayed for a predetermined time interval after back contact 60 of relay 4I-IR and front contact |5| of relay 4AGP, or contact 'l0 of mechanism 4CG become closed.

When a route has been cancelled and the cor responding locking relay ALS is held deenergized for a time by the time locking, it is desirable to inform the operator when it becomes energized and the locking is released. This is accomplished by causing the signal indicator to display a dashing red indication as long as the time locking is effective. This feature is illustrated by circuits of Fig. 1l such as the one for lamp r of indicator 4K which extends from terminal B over back contacts 40, H4 and 20 of relays CT, 4ALS and 4ER, and lamp r to terminal C.

Although I have traced but a few of the many possible operations of my apparatus, it is believed that the operation of setting up each of the remaining routes will be readily understood from the drawings without further explanation.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modications may be made therein within the scope of the appended claims without departing from the spirit and scope of my inven- V tion.

Having thus described my invention, what I claim is:

1. In an interlocking control system, a track layout including a plurality of track sections interconnected by track switches to form different trafc routes, signals for governing traffic movements over said routes, a route relay for each different route through the track layout, a pair of stick relays for each route end including an entrance relay for one end and an exit relay for the other end of each route, a control relay for each track switch, a track relay for each track section, a manually controllable pickup circuit for each said stick relay, a stick circuit for each entrance relay controlled by a front contact of the track relay of the adjacent section of the corresponding route and by a back contact of the exit relay for the same end of the route, a stick circuit for each exit relay including a front contact of the entrance relay for the opposite end `of the corresponding route and also including Athe winding of the route relay for such route, means controlled by each route relay when energized for operating the control relays for all of the track switches included in the corresponding routeto establish such route, and means controlled by each entrance stick relay andthe route relay controlled thereby 4for clearilO ill)

ing the signal governing traffic movements over such route.

2. In an interlocking control system, a track layout including a plurality of track sections `interconnected by track switches to form different trafli'c routes, signals for governing traffic movements over `said routes, a route relay Yfor each route, `a pair of stick relays for each route end'including an entrance relay for one end and an exit relay for the other end of each route, a manually controllable pick-up circuit for each -said stick relay, a stick circuit for each entrance relay controlled by a back contact of the exit relay for the same end of the corresponding route, a stick circuit for each exit relay controlled by a front contact of the entrance relay for `the opposite end of the corresponding route, `a route circuit for each route relay including front contacts of the entrance relay for one end and of the exit relay for the other end of the corresponding route, means preventing the closing of said route circuit if any switch of theroute is locked and the position of such switch is not in accordance with the route, and means controlled by each route relay when energized for operating one or more of the track switches as required to establish the corresponding route and for then clearing the signal for such route.

3. In an interlocking control system, a track layout including a plurality of track sections interconnected by track switches to form different traflic routes, signals for governing traflic movements over said routes, a route relay for each route, `a -pair of stick relays for each route end including an entrance relay for one end and an exit relay for the other end of each route, a manually controllable pick-up circuit for each `:said stick relay, a stick circuit for each entrance relay controlled by a back contact of the exit relay for the same end of the corresponding route, a stick circuit for each em't relay controlled by a front contact of the entrance relay for the opposite end of the corresponding route, a route circuit for one direction for each route relay including front contacts of the entrance relay for one end and of the exit relay for, the other end of the corresponding route, a route circuit for the opposite direction for each route relay including front contacts of the entrance relay for said other end and of the exit relay for said one end of the corresponding route, means preventing the vclosing of either of said route circuits if any switch of the route is locked and the position of such switch is not in accordance with the route, and means controlled by each route relay when energized for operating one or more of the track switches as required to establish the corresponding route and for then clearing the signal `for one direction or the `other for such route, dependent upon which entrance relay `is picked up. f

4. In an interlocking control system, a track layout including track switches adapted to be `arranged to form different traffic routes, route buttons for the ends of said routes each having a normal position and two control positions, a pair of stick relays for each route end including anjentrance relay for one end and an exit relay for th'eother end of each route, means for energizing the entrance relay for one end and the exit relay for the other end of a route when the two buttons for the ends of said route are both operated to corresponding control positions, a stick circuit for each entrance relay controlled by traic conditions,a stick circuit for each exit relay controlled by a front contact of the entrance relay for the other end of the same route, and means controlled by the entrance and exit relays for a route for operating the track switches as required to establish such route.

5. In an interlocking control system, a track layout including track switches adapted to be arranged to form different traiiic routes, route buttons for the ends of said routes each having a normal position and two control positions, a pair of stick relays for each route end including an entrance relay for one end and an exit relay for the other end of each route, means `for energizing the entrance relay for one end and the exit relay for the other end of a route when the two buttons for the ends of said route are both operated to one control position, means for energizing the entrance relay for said other end and the exit relay for said one end of said route when the two buttons for the end of said route are both operated to the other control position, a stick circuit for each entrance relay including a back contact of the exit relay for the same route end, a stick circuit for each exit relay controlled by a front contact of the entrance relay for the other end of the sam-e route, means controlled by the entrance and exit relays for a route for operating the track switches as required to establish such route, a signal at each end of each route for governing the movement of traic over `the route, and means controlled by the energized entrance relay for clearing the signal at the s-ame end of the corresponding route when such route is established.

6. In an interlocking control system, a 4track layout including track switches adapted to be arranged to form diierent traffic routes,` a locking relay for each switch energized only when conditions are proper for operating the switch, a switch control relay for each switch, a route button for each route end, a route relay for each different route through the track layout, a route circuit for each route relay closed in response to the operation of the route buttons for the two ends of the corresponding route provided the locking relay for each switch is energized or such switch already occupies the position required for said route, and means controlled by each route relay when energized for energizing the switch control relay for each switch of the route to thereby operate one or more of the track switches as may be required to establish the route.

7. In an interlocking control system, a track layout including track switches adapted to be arranged to form diirerent trafc routes, a locking relay for each switch energized only when `conditions are proper for operating the switch, a switch control relay for Veach switch, a route button for each route end, a route relay for each diierent route through the track layout, a route circuit for each route rel-ay closed in response to the operation of the route buttons for the two ends of the corresponding route each such circuit including a front contact of the locking relay for each switch of the route bridged by a switch indication contact closed only when the switch occupies the position required for said route, means controlled by each route relay when energized for Ienergizing the switch control relay for each switch of the route to thereby operate one or more of the track switches as m-ay be required to establish the route, and means rendered effective when a route is fully established to deenergize the locking relay for each switch of the route to open the locking relay contacts in the route circuits for each route which includes such switch.

8. In an interlocking control system, a plurality of routes through a track layout, each including a track switch, route buttons for the two opposite ends of each route each having a stop position and two control positions for opposite directions of trac, a locking relay energized only when conditions are proper for operating the track switch, a route circuit for each route over the switch including the winding of a route relay and contacts closed in response to the joint operation of the buttons for the opposite ends of the route to corresponding control positions and also including a front contact of said locking relay bridged by a switch indication contact closed only when the switch occupies the position required for the route, and means controlled by each route relay when energized for operating the track switch to said position,

9. In an interlocking control system, a plurality of routes through a track layout, each including a track switch, a route lever for each route end and each having a stop position and two control positions for opposite directions of traiic, an entrance stick relay and an exit stick relay for each route end, a route relay for each route, a route circuit for each direction for each route each including front contacts of the entrance and exit relays for a given direction for the two ends of such route, each route circuit also including the windings of the route relay and such exit relay for such route. a pick-up circuit for each entrance or exit stick relay controlled by the associated lever, the pick-up circuits for the entrance and exit relays for a given direction being closed in response to a momentary movement of the associated levers to corresponding positions irrespective of the condition of any route circuit, a stick circuit for each entrance relay including a back contact of the exit relay for the opposite direction for the same route, and means controlled by each route relay when energized to operate the track switch to a position in accordance with the route to permit traffic movements over the route in a direction dependent upon which of the two entrance relays for such route is energized.

10. In an interlocking control system, a plurality of routes through a track layout, each including a plurality of track switches, route buttons for the two opposite ends of each route, a locking relay for each switch, a route circuit for each route including the winding of a route relay and contacts closed in response to the joint operation of the buttons for the opposite ends of the route and also including a front contact of the locking relay for each switch of the route, means controlled by each route relay when energized to operate one or more of the track switches as required to establish the route, an indication contact for each switch which closes to bridge the front Contact of the associated locking relay in the route circuit when such switch occupies the position required for the route, and means effective when each switch assumes the position required for the route to deenergize the associated locking relay.

11. In an interlocking control system, a plurality of routes through a track layout, each including a track switch, route buttons for the two opposite ends of each route, a locking relay for each switch, a route circuit for each route including the winding of a route relay and contacts closed in response to the joint operation of the buttons for the opposite ends of the route and also including a front contact of said locking relay, means controlled by each route relay when energized to operate one or more of the track switches as required to establish the route, an indication contact for each which closes to bridge the front contact of the associated locking relay in the route circuit when such switch occupies the position required for the route, a signal for each route for governing traic movements over the route, a signal control relay for each signal controlled by the route relay for the corresponding route and by switch indication contacts which close when the switches assume the positions required for the route, and means effective When a signal control relay becomes energized to release the locking relay for each switch of the corresponding route and to clear the signal for such route in response to the release of said locking relays.

l2. In an inerlocking control system, a plurality of routes through a track layout, each including a track switch, route buttons for the two opposite ends of each route, a locking relay which when deenergized prevents operation of the track switch, a route circuit for each route over the switch including the winding of a route relay and contacts closed in response to the joint operation of the buttons for the opposite ends of the route and also including a front contact of said locking relay, means controlled by each route relay when energized to operate the switch to the position required for the corresponding route, a switch indication contact which closes to bridge the front contact of said locking relay in the route circuit when the switch assumes the position required for the route, a signal for governing traffic movements over the route, a signal control relay controlled by said route relay and by a switch indication contact which closes when the switch assumes the position required for the route, means eiective when the signal control relay becomes energized to release said locking relay, and a circuit for clearing said signal including a front contact of said signal control relay and a back contact of said locking relay.

13. In an interlocking control system, a plurality of routes through a track layout, each including a track switch, route buttons for the two opposite ends of each route, a locking relay which when deenergized prevents operation of the track switch, a route relay for each route over the switch, a route circuit for each route relay including a front contact of said locking relay and contacts closed in response to the joint operation of the buttons for the opposite ends of the route, means controlled by each route relay when energized to operate the switch to the position required for the route, a signal for governing traiiic movements over the route, a signal control relay controlled by said route relay and by a switch indication contact which closes when the switch assumes the position required for the route, means effective when the signal control relay becomes energized to release said locking relay, and means controlled by said signal control relay and4 rendered effective when said locking rela-y releases for clearing said, signal.

14. In an interlocking control system, a, track layout comprising a plurality of track sections interconnected by track switches to form different traffic routes, a track diagram comprising a miniature representation of the track layout, a plurality of groups of lamps included in the tracks of said diagram for displaying illuminated representations of the different routes through said layout, route control means for each route effective when energized to operate one or more of the track switches as required to establish the route, means controlled b-y said route control means for lighting one or more of said lampsv individually each to indicate that a particular track switch is being operated, each such lamp being lighted as long as the track switch is in transit from one operated position to another, and means eiective when a route is fully established by said route control means for lighting all of the lamps of the corresponding group.

15. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form different traffic routes, a track diagram comprising a miniature representation of the track layout, a plurality of groups of lamps included in the tracks of said diagram for displaying illuminated representations of the different routes through said layout, route control means for each route effective when energized to operate one or more of the track switches as. required to establish the route, means for intermittently lighting one or more of said lamps individually to indicate by flashing indications which of the switches are beng operated, and means effective when all of the track ,switches of the route have assumed positions in accordance with the route for steadily lighting the lamps of a selected group to display a representation of the established route on the track diagram.

16, In combination, a detector section of railway track including a track switch, a track relay for said section, a track diagram arranged to form a miniature representation of said detector section and provided with two substantially linear translucent portions including one for each branch track extending in the trailing direction from the track switch, switch control means for operating said switch to each of its extreme positions, means controlled by the track switch for intermittently illuminating one of said portions to display a flashing indication when the switch is not in correspondence with said control means, means controlled by the track switch and by a front contact of the track relay for at "times steadily illuminating a selected one of said portions to indicate an available route over the track switch, and means controlled by the track switch and by a back contact of the track relay for at times differently illuminating said selected portion to indicate that said route is occupied by a train.

1'7. In combination, a detector section of railway track including a track switch, a track relay for said section, a track diagram arranged to form a miniature representation of said detector section and provided with two substantially linear translucent portions including one for each branch track extending in the trailing direction from'the track switch, switch control means for operating said switch to each of its extreme positions, means controlled jointly by the track switch and its control means for intermittently illuminating one of saidportions; to display a flashing indication when the switch is not in correspondence with said control means, and means effective when the switch and said control means are both operated to their normal or reverse positions for steadily illuminating the corresponding one of said portions to indicate an available route over the switch.

18. In combination, a track layout including a plurality of tracksections connected by track switches, a track diagram comprising a plurality of substantially linear translucent portions arranged to form a miniature representation of said sections, two lamps of different colors for each portion for illuminating such portion, route control means for operating the track switches to establish different traic routes through the track layout, means controlled by each track switch to intermittently light one lamp for a portion adjacent the representation of the switch to display a flashing indication when the switch is clisplaced from its proper normal or reverse position, means effective when a route is established by an operation of said control means` to steadily light one lamp for each portion of the corresponding route to indicate such route by a substantially continuous illuminated line on the track diagram, and means effective as each section of the route becomes occupied by a train to extinguish said one lamp for each portion and to light the other lamp for each portion of the representation of such section, such other lamps becoming extinguished when such section is vacated by the train.

19. In an interlocking control system, a detector section of railway track containing a track switch, a track relay for said section, a signal for each direction for governing the movement of trlaflic over a traflic route including said switch, an approach locking relay controlled by each signal and energized only when the signal indicates stop, a switch locking relay controlled'by iront contacts of said track relay and of said approach locking relays, route buttons for the two opposite ends of said route, an entrance relay selectively controllable by each route button -to establish a particular traffic direction, a route relay, a pick-up circuit for said route relay controlled jointly by the entrance relay for one end of said route and by the route button for the other end of said route, a stick circuit for said route relay controlled by said entrance relay only, means controlled by said route relay when energized for operating the track switch to the position required for said route, means controlled by said entrance relay for releasing the associated approach locking relay when the track switch assumes such position, and a signal circuit controlled by said route relay and including a back Contact of said switch locking relay for clearing the signal for the traffic direction established by said entrance relay, said signal circuit also including a iront contact of the approach locking relay for the signal for the other direction.

20. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form dilerent traiiic routes, a track relay for each section, a miniature track diagram of said track layout having linear `portions representing the track sectie-ns, route control means for each route eiTective when energized to operate the track switches as required to establish the route, a plurality of directional stick relays including one for each direction for each track section, means controlled by the track switches when a route has been established for successively energizing the directional stick relays for one direction including o-ne relay for each section of such route, means controlled by each directional stick relay when energized for illuminating the corresponding portion of the track diagram, and means controlled by the track relay for each section for maintaining the directional stick relay for the 'same section energized until such section is vacated.

21. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form diierent traflic routes, a track relay for each section, a miniature track diagram having linear portions representing the track sections, means for illuminating said portions, route control means for each route for operating the track switches as required to establish the route, an indication relay for each track section, means controlled by the track switches when a route has been established by its control means for selectively actuating a plurality of said indica.- tion relays including one for each section of such route, means controlled by each actuated indication relay effective to energize the means for illuminating the corresponding portions of the track diagram, and means controlled by the track relay for each section for maintaining the corresponding indication relay actuated un- ,til such section is vacated.

22. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form different tralc routes, a track relay for each section, a

'miniature track diagram having linear portions representing the track sections, means for illuminating said portions, route control means for each route for operating the track switches as required to establish the route, an indication relay for each track section, means controlled by the track switches when a route has been established by its control means for selectively actuating a plurality of said indication relays including one for eao'h section of such route, means controlled by each actuated indication relay effective to energize the means for illuminating the corresponding portions of the track diagram, means for cancelling a route when a train enters it, and means controlled by the indication relays and track relays for maintaining said illumination for each section only until the train enters such section.

23. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form different traiiic routes, a track relay for each section, a miniature track diagram having linear portions representing the track sections, Atwo different means for illuminating each of said portions, route control means for each route for operating the track switches as required to establish such route, an indication relay for each track section, means controlled by the track switches when a route has been established by its control means for selectively actuating a plurality of said indication relays including one for each section of such route, means controlled by each actuated indication relay for energizing one means for illuminating the corresponding portion of the track diagram, said portions collectively displaying a representation of the established route, means for cancelling a route when the train enters it, means controlled by the indication relays and track relays for maintaining said illumination for each section only until the train enters such section, and means for then energizing the other means for illuminating such section as long as it is occupied by the train.

24. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form different traflic routes, a track relay for each section, a miniature track diagram having linear portions representing the track sections, route control means for each route for operating the track switches as required to establish such route, a stick relay for each track section having a pickup circuit and a stick circuit, means controlled by the track switches when a route is established for preparing the pick-up circuits for a series of said stick relays including one relay for each section of said route, means controlled by the route control means for completing the pick-up circuit for the rst relay of the series, means controlled by each stick relay when energized for completing the pick-up circuit for the next relay of the series, means for closing the stick circuit for each stick relay when the corresponding track relay releases, and means-controlled by each stick relay for illuminating the corresponding portion of the track diagram.

25. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form diierent trailic routes, a miniature track diagram of said track layout having linear portions representing the track sections, route control means for each route eiective when energized to operate the track switches as required to establish such route, means controlled by each route control means and by the track switches of the corresponding route to illuminate the portions of the diagram representing such route to indicate when each switch of a route occupies its proper normal or reverse position, and means eiiective in the event a track switch becomes displaced from its proper normal or reverse position even though said route control means is not operated for distinctively illuminating a portion of said diagram adjacent the representation of said switch to indicate the condition of said switch.

26. In an interlocking control system, a track layout comprising a plurality of track sections interconnected by track switches to form diierent trac routes, signals for governing traic movements over said routes, route control means for each route eiective when energized to operate the track switches as required to establish such route, signal control means for each route energized when a route is fully established by the operation of the track switches as required for such route, locking means for each switch effective when deenergized to prevent its operation, means responsive to the energization of the signal control means for a route for releasing the locking means for each switch of the route, means controlled by the locking means for the switches of a route when released to prevent the operation of the route control means for any conicting route, and means for clearing the signal for a route controlled by the signal control means for the route and rendered effective when the locking means for each switch of the route is released.

27. In an interlocking control system, a track layout including track switches adapted to be arranged to form dierent traiiic routes, route buttons for the ends of said routes each having a by the entrance and exit relays for a route for operating the track switches as required to establish such route, and means responsive to a subsequent operation of the entrance button toits opposite control position to release said energized entrance and exit relays to cancel said route.

RONALD A. MCCANN. 

